125 research outputs found
Cost-effectiveness of HBV and HCV screening strategies:a systematic review of existing modelling techniques
Introduction:
Studies evaluating the cost-effectiveness of screening for Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) are generally heterogeneous in terms of risk groups, settings, screening intervention, outcomes and the economic modelling framework. It is therefore difficult to compare cost-effectiveness results between studies. This systematic review aims to summarise and critically assess existing economic models for HBV and HCV in order to identify the main methodological differences in modelling approaches.
Methods:
A structured search strategy was developed and a systematic review carried out. A critical assessment of the decision-analytic models was carried out according to the guidelines and framework developed for assessment of decision-analytic models in Health Technology Assessment of health care interventions.
Results:
The overall approach to analysing the cost-effectiveness of screening strategies was found to be broadly consistent for HBV and HCV. However, modelling parameters and related structure differed between models, producing different results. More recent publications performed better against a performance matrix, evaluating model components and methodology.
Conclusion:
When assessing screening strategies for HBV and HCV infection, the focus should be on more recent studies, which applied the latest treatment regimes, test methods and had better and more complete data on which to base their models. In addition to parameter selection and associated assumptions, careful consideration of dynamic versus static modelling is recommended. Future research may want to focus on these methodological issues. In addition, the ability to evaluate screening strategies for multiple infectious diseases, (HCV and HIV at the same time) might prove important for decision makers
18S rRNA is a reliable normalisation gene for real time PCR based on influenza virus infected cells
Background: One requisite of quantitative reverse transcription PCR (qRT-PCR) is to normalise the data with an
internal reference gene that is invariant regardless of treatment, such as virus infection. Several studies have found
variability in the expression of commonly used housekeeping genes, such as beta-actin (ACTB) and
glyceraldehyde-3-phosphate dehydrogenase (GAPDH), under different experimental settings. However, ACTB and
GAPDH remain widely used in the studies of host gene response to virus infections, including influenza viruses. To
date no detailed study has been described that compares the suitability of commonly used housekeeping genes in
influenza virus infections. The present study evaluated several commonly used housekeeping genes [ACTB, GAPDH,
18S ribosomal RNA (18S rRNA), ATP synthase, H+ transporting, mitochondrial F1 complex, beta polypeptide (ATP5B)
and ATP synthase, H+ transporting, mitochondrial Fo complex, subunit C1 (subunit 9) (ATP5G1)] to identify the most
stably expressed gene in human, pig, chicken and duck cells infected with a range of influenza A virus subtypes.
Results: The relative expression stability of commonly used housekeeping genes were determined in primary
human bronchial epithelial cells (HBECs), pig tracheal epithelial cells (PTECs), and chicken and duck primary
lung-derived cells infected with five influenza A virus subtypes. Analysis of qRT-PCR data from virus and mock
infected cells using NormFinder and BestKeeper software programmes found that 18S rRNA was the most stable
gene in HBECs, PTECs and avian lung cells.
Conclusions: Based on the presented data from cell culture models (HBECs, PTECs, chicken and duck lung cells)
infected with a range of influenza viruses, we found that 18S rRNA is the most stable reference gene for normalising
qRT-PCR data. Expression levels of the other housekeeping genes evaluated in this study (including ACTB and
GPADH) were highly affected by influenza virus infection and hence are not reliable as reference genes for RNA
normalisation
Centralised Design and Production of the Ultra-High Vacuum and Laser-Stabilisation Systems for the AION Ultra-Cold Strontium Laboratories
This paper outlines the centralised design and production of the
Ultra-High-Vacuum sidearm and Laser-Stabilisation systems for the AION
Ultra-Cold Strontium Laboratories. Commissioning data on the residual gas and
steady-state pressures in the sidearm chambers, on magnetic field quality, on
laser stabilisation, and on the loading rate for the 3D Magneto-Optical Trap
are presented. Streamlining the design and production of the sidearm and laser
stabilisation systems enabled the AION Collaboration to build and equip in
parallel five state-of-the-art Ultra-Cold Strontium Laboratories within 24
months by leveraging key expertise in the collaboration. This approach could
serve as a model for the development and construction of other cold atom
experiments, such as atomic clock experiments and neutral atom quantum
computing systems, by establishing dedicated design and production units at
national laboratories.Comment: 27 pages, 21 figure
Tracking the international spread of SARS-CoV-2 lineages B.1.1.7 and B.1.351/501Y-V2
Publisher Copyright: © 2021 O'Toole Á et al.Late in 2020, two genetically-distinct clusters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) with mutations of biological concern were reported, one in the United Kingdom and one in South Africa. Using a combination of data from routine surveillance, genomic sequencing and international travel we track the international dispersal of lineages B.1.1.7 and B.1.351 (variant 501Y-V2). We account for potential biases in genomic surveillance efforts by including passenger volumes from location of where the lineage was first reported, London and South Africa respectively. Using the software tool grinch (global report investigating novel coronavirus haplotypes), we track the international spread of lineages of concern with automated daily reports, Further, we have built a custom tracking website (cov-lineages.org/global_report.html) which hosts this daily report and will continue to include novel SARS-CoV-2 lineages of concern as they are detected.Peer reviewe
Ice slurry crystallization based on kinetic phase-change modeling
Most crystallization models for ice slurries are based on the equilibrium thermodynamic approach, an assumption that is not made a priori here. We present results of simulations grounded on classical nucleation theory and crystal growth included in global Nakamura-type kinetics coupled with the one-dimensional nonlinear heat equation, another way to model the phase change. The work focuses on ice slurry crystallization using kinetic tools integrating the temperature glide for mixtures (i.e., the solid liquid equilibrium temperature T-f depends on the residual fluid\u27s solute concentration) without any equilibrium assumption. The heat-transfer phenomena in the experimental device are first determined, and then the parameters of kinetic function of crystallization are identified for pure water samples and then for 15 wt% monopropylene glycol (MPG) - water mixtures. An inverse method is implemented with a genetic algorithm to determine the kinetic parameters. (C) 2010 Elsevier Ltd and IIR. All rights reserved
ICE SLURRY CRYSTALLISATION BASED ON A KINETIC PHASE CHANGE MODELISATION
Most crystallization models for ice slurries are based on approaches of thermodynamic equilibrium. This paper presents results of simulation grounded on a global Nakamura type kinetics coupled with the 1D non-linear heat equation, another way to model the phase change. The model takes into account the energy needed at the different steps of the transformation, from nucleation to crystal growth. The work focuses on the study of the ice slurry crystallisation using kinetic tools integrating the temperature glide for mixtures (i.e.. crystallisation equilibrium temperature T-f depends on residual fluid\u27s solute concentration). The phenomena of transfers relative to the experimental device are determined at first, and then parameters of kinetic function of crystallisation are identified for pure water samples and for water-mono propylene glycol (MPG) mixtures (15% MPG mass fraction). We used an inverse method implemented with a code of genetic algorithm
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